Cardiology/Angiology

Question 1

Atrial cardiomyocytes release __________________________ when stretched (i.e., at higher BPs) → ↑ water and sodium excretion by the kidneys → ↓ BP

Answer 1

atrial natriuretic peptide (ANP)

Question 2

Why does damaged myocardial tissue eventaually lead to increased risk of cardiac arrythmias.

Answer 2

Damaged myocardial tissue is replaced by noncontractile scar tissue (fibrosis) that does not conduct electrical impulses well and, thus, predisposes to cardiac arrhythmias.

Question 3

Why might pericarditis result in left neck/arm/shoulder pain?

Answer 3

Because of the sensory innervation of the pericardium by the phrenic nerve, pericarditis can result in referred pain to the neck, arms, or shoulders (often the left side).

Question 4

What nerve provides sensory innervation to the pericardium?

Answer 4

The phrenic

Question 5

Why is it difficult to treat endocarditis involving the valves?

Answer 5

The valves are mostly vessel-free, with nutrition derived from the surrounding blood This makes valvular involvement in endocarditis difficult to treat because both the cells of the immune system and antibiotics typically reach sites of infection via the circulatory system.

Question 6

What major tissue in embyology does the heart originiate from?

Answer 6

All three major layers of the heart orginiate from the mesoderm

Question 7

Valve located between right atrium and right ventricle

Answer 7

Tricuspid (Consists of three leaflets)

Question 8

Valve located between left atrium and ventricle

Answer 8

Mitral valve/Biscuspid Valve

Question 9

When do the coronary arteries fill with blood?

Answer 9

The coronary arteries fill with blood during diastole because they are compressed during ventricular systole.

Question 10

Most commonly occluded coronary artery

Answer 10

The LAD is the most commonly occluded coronary artery and is often referred to as the “widow maker” due to the high mortality rate associated with LAD infarction.

Question 11

What coronary artery has a propensity to increase cardiac arruthmia w/ooclusion?

Answer 11

The RCA usually supplies the heart’s conduction system (sinus and AV node) so that stenosis or occlusion of this vessel often leads to cardiac arrhythmias.

Question 12

Chronotropy

Answer 12

The ability to influence heart rate. Positively chronotropic drugs (e.g., adrenaline) increase heart rate, while negatively chronotropic drugs (e.g., beta blockers) decrease heart rate.

Question 13

Inotropy

Answer 13

The ability to influence the force of cardiac muscle contraction. Positively inotropic drugs (e.g., catecholamines) increase the force of contraction, while negatively inotropic drugs (e.g., beta blockers) decrease the force of contraction.

Question 14

Dromotropy

Answer 14

The ability to influence the conductivity of cardiac tissue. Positively dromotropic drugs (e.g., catecholamines) increase the rate of conduction of an electrical impulse through cardiac tissue, while negatively dromotropic drugs (e.g., digoxin) decrease the rate of conduction of an electrical impulse through cardiac tissue.

Question 15

What are the layers of the heart?

Answer 15

Endocardium
Myocardium
Epicardium: connective tissue layer attached to the outside of the myocardium, i.e., visceral layer of serous pericardium
Pericardium: membrane that directly surrounds the heart

Question 16

What is the frank starling law/principle?

Answer 16

A principle that describes the relationship between end-diastolic volume and cardiac stroke volume. Cardiac contractility is directly related to the wall tension of the myocardium; an increase in end-diastolic volume will cause the myocardium to stretch, which increases contractility and results in increased stroke volume.

Question 17

What is stroke volume?

Answer 17

Volume of blood pumped by the left or right ventricle in a single heartbeat

SV = end-diastolic volume (EDV) − end-systolic volume (ESV)

Question 18

How do you calculate stroke volume?

Answer 18

SV = end-diastolic volume (EDV) − end-systolic volume (ESV)

Question 19

What is ejection fraction?

Answer 19

Ejection fraction (EF): the proportion of EDV ejected from the ventricle

–> EF = SV / EDV = (EDV - ESV)/EDV
–> Normally 50–70%

Question 20

What does ejection tell us?

Answer 20

Serves as an index of myocardial contractility: e.g., ↓ myocardial contractility → ↓ EF (seen in systolic heart failure, where EF is < 40%)

Question 21

How does ejection fraction differ in systolic versus diastolic heart failure?

Answer 21

Systolic: EF is LOW
Diastolic: EF is NORMAL

Question 22

the rate at which blood flows back to the heart, which typically equals cardiac output

Answer 22

venous return

Question 23

How do you calculate cardiac output?

Answer 23

Cardiac output (CO) = heart rate (HR) × stroke volume (SV)

Question 24

Fick principle

Answer 24

Cardiac output is proportional to the quotient of the total body oxygen consumption and the difference in oxygen content of arterial blood and mixed venous blood.

Cardiac output (CO) = oxygen consumption rate/arteriovenous oxygen difference = (O2 consumption)/(arterial O2content - venous O2 content)

Question 24

How do you calc mean arterial pressure?

Answer 24

MAP = cardiac output (CO) × total peripheral resistance (TPR)

Question 24

Why does stroke volume decrease as HR increases?

Answer 24

As HR increases, diastole is shortened (filling time is decreased), which decreases SV due to less filling time.

Question 24

The force against which the ventricle contracts to eject blood during systole. It is primarily determined by the blood pressure in the aorta, which is influenced by total peripheral resistance

Answer 24

Afterload

Question 25

What is normal pressure for the right atrium?

Answer 25

5 mmhg

Question 26

What is normal Right ventricle (pulmonary artery pressure)?

Answer 26

25/5 mm Hg

Question 27

An indirect measure of left atrial pressure and, therefore, an estimation for preload.

Answer 27

Pulmonary capillary wedge pressure

Question 28

Normal pressure for left atrium?

Answer 28

Left atrium (pulmonary capillary wedge pressure): < 12 mm Hg (higher than left ventricular pressure in mitral stenosis)